Answering the Question: How Can I Get My Ripped CDs to Play As High a Volume as My Purchased iTunes Songs?

Whenever I make playlists consisting of songs purchased from iTunes and CDs ripped into my computer (and now in my iTunes library), I notice the ripped songs always play at a lower volume on my iPod. This is especially apparent through headphones. My wife notices the same thing. Ripped music is more muted and at a lower volume. 

What gives? Is this Apple's method for getting us to re-buy songs we already own on CD from iTunes? 

Reader "JG" answered my question:

Just enable "Sound Check" in iTunes *and* on your iPod. Enabling it in iTunes will scan your library and determine the volume for each track (this can take a long time if your library is huge). When that's done, sync your iPod and enable Sound Check on the iPod. During playback it will automatically adjust for each track. Just google "iTunes iPod Sound Check." This feature was added several generations ago (actually iTunes 3), but I guess it's not on by default. Good Macworld article about this subject: Adjust the Volume of iTunes and iPod Tracks.